Genome-wide association mapping for high temperature tolerance in wheat through 90k SNP array using physiological and yield traits.

Dissecting the genetic basis of physiological and yield traits against tolerance to heat stress is an essential in wheat breeding programs to boost up the wheat yield for sustainable food security. Herein, a genome-wide association study (GWAS) was performed to reveal the genetic basis of heat tolerance using high-density Illumina 90K Infinium SNPs array through physiological and yield indices. These indices were phenotyped on a diverse panel of foreign and domestic genotypes of Pakistan, grown in normal and heat-stressed environments. Based on STRUCTURE analysis, the studied germplasm clustered into four sub-population. Highly significant variations with a range of moderate (58.3%) to high (77.8%) heritability was observed under both conditions. Strong positive correlation existed among physiological and yield related attributes. A total of 320 significant (-log10 P ≥ 3) marker-trait associations (MTAs) were identified for the observed characters. Out of them 169 and 151 MTAs were recorded in normal and heat stress environments, respectively. Among the MTA loci, three (RAC875_c103017_302, Tdurum_contig42087_1199, and Tdurum_contig46877_488 on chromosomes 4B, 6B, and 7B respectively), two (BobWhite_c836_422 and BS00010616_51) and three (Kukri_rep_c87210_361, D_GA8KES401BNLTU_253 and Tdurum_contig1015_131) on chromosomes 5A, 1B, and 3D at the positions 243.59cM, 77.82cM and 292.51cM) showed pleiotropic effects in studied traits under normal, heat-stressed and both conditions respectively. The present study not only authenticated the numerous previously reported MTAs for examined attributes but also revealed novel MTAs under heat-stressed conditions. Identified SNPs will be beneficial in determining the novel genes in wheat to develop the heat tolerant and best yielded genotypes to fulfill the wheat requirement for the growing population.

Genome-wide association mapping of bread wheat genotypes using yield and grain morphology-related traits under different environments.

Depleting water resources and increasing global temperature due to climate change are major challenges to agriculture and food security worldwide. Deciphering the underlying mechanisms of traits contributing to grain development and yield is essential for the development of climate-resilient cultivars. Therefore, this study assessed 105 bread wheat genotypes grown under control, drought, and heat-stress conditions for two crop seasons and performed a genome-wide association study (GWAS) using a 90k SNP array. The genotypes showed significant trait differences under all environmental conditions. Highly significant variation was observed, with moderate (50.09%) to high (76.19%) heritability in the studied germplasms. The studied traits were all also significantly positively correlated. A total of 541 significant associations (p ≤ 10-3) between marker and trait (MTAs) were observed after crossing the FDR <0.05 threshold for all traits. Among these, 195, 179, and 167 significant MTAs were detected under control, drought, and heat-stress conditions, respectively. Under the control and drought conditions, pleiotropic loci BS00010616_51 and BS00010868_51 were observed on chromosomes 7B and 1B situated at 186.24 cM and 35.47 cM, respectively. Pleiotropic loci BS00010868_51, Kukri_c11154_1723, and Ex_c10068_1509 were identified on chromosomes 1B, 5B, and 2A, respectively, under control and heat stress conditions. A stable and consistent locus (Excalibur_c20796_395) on chromosome 7A, located at 372.34 cM, was also linked to grain morphology and yield-related attributes in control, drought, and heat-stress conditions. The results of the current study confirmed several previously reported MTAs for the traits under consideration and identified new MTAs under harsh climatic conditions. These SNPs will aid in the discovery of novel genes in wheat. SNPs showing significant associations may be used in marker-assisted selection and allow the development of drought- and heat-tolerant genotypes with high yields to address global food security concerns.

Effect of different planting pattern arrangements on soil organic matter and soil nitrogen content under a maize/soybean strip relay intercropping system.

Assessing the spatial distribution of organic matter and total nitrogen in soil is essential for management and optimum utilization of fertilizers. Therefore, the present field experiment was conducted to evaluate the impact of different planting pattern arrangements on the spatial distribution of soil total nitrogen and organic matter content under a maize/soybean strip relay intercropping system. The planting was arranged in a manner such that soil sampling could be done from continuous maize/soybean relay strip intercropping (MS1), maize/soybean relay strip intercropping in rotation (MS2), traditional maize/soybean intercropping (MS3), sole maize (M), sole soybean (S), and fallow land (FL) from 2018 to 2020. The results showed significant variations for soil organic matter and total nitrogen content under different planting pattern arrangements of maize and soybean in the strip relay intercropping system. Across all systems, the highest soil organic matter (29.19 g/kg) and total nitrogen (10.19 g/kg) were recorded in MS2. In contrast, the lowest soil organic matter (1.69 g/kg) and total nitrogen (0.64 g/kg) were observed in FL. Soil organic matter and total nitrogen in MS2 increased by 186.45% and 164.06%, respectively, when compared with FL. Soil organic matter and total nitrogen in MS2 increased by 186.45% and 164.06%, respectively, when compared with FL. Furthermore, under MS2, the spatial distribution of soil organic matter was higher in both maize and soybean crop rows as compared with other cropping patterns, whereas the soil total nitrogen was higher under soybean rows as compared with maize in all other treatment. However, correlation analysis of the treatments showed variations in organic matter content. It can be concluded that different planting patterns can have varying effects on soil organic matter and total nitrogen distribution under the strip relay intercropping system. Moreover, it is recommended from this study that MS2 is a better planting pattern for the strip relay intercropping system, which can increase the spatial distribution of soil organic matter and total nitrogen, thereby improving soil fertility, C:N ratio, and crop production. This study will serve as a foundation towards the scientific usage of chemical fertilizers in agricultural sector.

Variations in Morphological Characters and Antioxidant Potential of Different Plant Parts of Four Ziziphus Mill. Species from the Cholistan.

Genus Ziziphus (Z.) contains various important species in tropical and subtropical regions that are globally famous for their food and medicinal uses. However, no comprehensive study was available on the morphology and phytochemistry of Ziziphus species, mainly under different growth conditions, i.e., irrigated and desert (Cholistan). Therefore, this study was carried out to evaluate the morphological and phytochemical characteristics of Ziziphus species, i.e., Z. jujuba, Z. mauritiana, Z. spina-christi, and Z. nummularia, found in the irrigated and desert conditions. Our results revealed significant variations for most of the measured parameters, showing a large-scale diversity among Ziziphus species under irrigated and desert conditions. Specifically, Ziziphus species showed better morphology of all measured parameters of leaves and fruits under irrigated conditions compared to desert conditions, indicating that the optimum water availability in irrigated conditions improved the morphological parameters of Z. species. Meanwhile, among all Ziziphus species, the maximum leaf length (7.4 cm), leaf width (4.1 cm), leaf area (30.6 cm2), and leaf petiole length (1.3 cm) were observed for Z. jujuba, and the highest leaf dry weight (55.4%) was recorded for Z. mauritiana. Similarly, the highest fruit length (3.9 cm), fruit stalk length (1.5 cm), fruit diameter (3.6 cm), fruit width (3.8 cm), fruit area (66.1 cm2), seed length (2 cm), and seed diameter (1.1 cm) were measured for species Z. jujuba, while the maximum fruit dry weight (49.9%) and seed width (1.4 cm) were recorded for species Z. nummularia. Interestingly, compared to irrigated conditions, higher values of bioactive contents, i.e., phenol, flavonoid, and antioxidant activity, in fruits and leaves of Ziziphus species under desert conditions indicated the positive impact of desert climate on the phytochemistry of the Z. plants. Among Ziziphus species, Z. nummularia accumulated the maximum fruit phenols (304.4 mg GAE/100 g), leaf phenols (314.2 mg GAE/100 g), fruit flavonoids (123.7 mg QE/100 g), and leaf flavonoids (113.4 mg QE/100 g). Overall, this study demonstrated the significant morphological and phytochemical variations of the Ziziphus species under irrigated and desert conditions, which could be utilized for future studies to improve the production and medicinal potential of the Ziziphus, especially in desert areas.

First report of Alternaria alternata causing Alternaria leaf spot of Fig in Pakistan.

Fig (Ficus carica) is a species of flowering plants within the mulberry family. During June 2020, leaf spots were observed on several fig plants (31°26'15.0"N 73°04'25.6"E) at the University of Agriculture, Faisalabad, Pakistan. Early symptoms were small, oval to circular, light brown, sunken spots that were uniformly distributed on the leaves. Spots gradually enlarged and coalesced into circular to irregular dark brown to black spots that could be up to 3cm diam. with no or small sized fruit. Disease incidence was approximately 25%. To identify the causal agent of the disease, 15 symptomatic leaves were collected. Small pieces from all diseased samples were removed from the margin between healthy and diseased tissues were surface disinfested in 70% ethanol for 2 min, rinsed three times with sterile distilled water, plated on Potato dextrose agar and incubated at 25 ± 2°C with a 12-h photoperiod. Fungal isolation on PDA medium frequency was 95% from diseases leaves. Morphological observations were made on 7- day- old single-spore cultures. The colonies initially appeared light grayish which turned sooty black in color. All fungal isolates were characterized by small, short-beaked, multicellular conidia. The conidia were ellipsoidal or ovoid and measured 9 to 25 µm × 5 to 10 µm (n = 40) with longitudinal and transverse septa. The morphological characters matched those of Alternaria alternata (Simmons et al. 2007). Genomic DNA of a representative isolate (FG01-FG03) was extracted using DNAzol reagent (Thermo Fisher Scientific MA, USA) and PCR amplification of the internal transcribed spacer (ITS) rDNA region, was performed with primers ITS1/ITS4 (White et al. 1990), partial RNA polymerase II largest subunit (RPB2) with RPB2-5F/RPB2-7cR (Liu et al. 1999) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene regions was performed with gpd1/gpd2 (Berbee et al. 1999). The obtained sequences were deposited in GenBank with accession numbers MW692903.1 to MW692905.1 for ITS-rDNA gene, MZ066731.1 to MZ066733.1 for RPB2 and MZ066728.1 to MZ066730.1 for GAPDH. BLASTn analysis showed 100% identity with the submitted sequences of A. alternata for ITS rDNA, RPB2, and GAPDH. To confirm pathogenicity, 2-month-old 15 healthy potted F. carica plants were sprayed at true leaf stage with conidial suspension by using an atomizer in a greenhouse. Each representative A. alternata isolate (FG01-FG03) was inoculated on every three plants with conidial suspensions (106 conidia/ml; obtained from 1-week-old cultures) amended with 0.1% (vol/vol) of Tween 20 until runoff (1.5 to 2 ml per plant) whereas, three control plants were sprayed with sterile distilled water amended with 0.1% Tween 20. All plants were incubated at 25 ± 2°C in a greenhouse, and the experiment was conducted twice. After 10 days of inoculation, each isolate induced leaf spots similar to typical spots observed in the field, whereas the control plants remained symptomless. The fungus was re-isolated from symptomatic tissues and reisolation frequency was 100%. Re-isolated fungal cultures were again morphologically and molecularly identical to A. alternata, thus fulfilling Koch's postulates. Previously, A. alternata has been reported cause fruit disease of fig in Pakistan and California, USA (Alam et al. 2021; Latinovic et al. 2014). To our knowledge, this is the first report of A. alternata causing leaf spot on common fig in Pakistan. In Pakistan, fig is widely grown for drying, and this disease may represent a threat to fig cultivation.

Adult congenital heart disease: frequency, risk factors and outcomes of acute kidney injury in postoperative period.

BACKGROUND: Acute kidney injury (AKI) after surgery for congenital heart disease (CHD) in adults is poorly studied despite being well-recognized as a postoperative complication after cardiac surgery in adults. The primary aim of our study was to determine the frequency of AKI in adults undergoing surgery for CHD. We also aimed to determine risk factors and predictors of AKI in this patient population, and to explore outcomes in terms of duration of mechanical ventilation, intensive care unit (ICU) stay, and hospital stay. METHODS: This retrospective cross-sectional study included all adult patients (18 years) who underwent cardiac surgery with cardiopulmonary bypass for their congenital heart problems from January 2011 to December 2016 in a tertiary-care private hospital. RESULTS: A total of 166 patients with a mean age of 32.05 ± 12.11 years were included in this study. The postoperative course was complicated by AKI in 29.5% of patients. Thirty-two percent of these patients had moderate-to-severe kidney disease. Two patients (4%) developing AKI required renal replacement therapy in the form of transient hemodialysis. All patients in our study showed complete resolution of AKI, with no mortalities in the postoperative period. On univariable analysis, (Risk adjusted classification for congenital heart surgery-1) RACHS-1 category 2 and 3, aortic valve replacement, preoperative creatinine clearance, ventricular septal defect closure, cardiopulmonary bypass time, aortic cross-clamp time, intra-operative excessive blood loss, intra-operative ionotropic score, and postoperative hypotension were found to be significant predictors for the development of AKI. On age-adjusted multivariable analysis, RACHS-1 category 2 (OR = 3.49; CI = 1.22-9.95) and category 3 (OR = 3.28 = 1.15-9.36), and intra-operative excessive blood loss (OR = 2.9; CI = 1.07-7.85) were significant predictors of AKI development in the postoperative period. Moreover, development of AKI postoperatively was a predictor of a significantly longer cardiac intensive care unit (CICU) stay (OR = 1.21; CI = 1.08-1.37). CONCLUSION: We found that preoperative creatinine clearance, ACC time, intraoperative excessive blood loss, and RACHS-1Category 2 and 3 are potential risk factors for postoperative AKI development. Moreover, patients who develop AKI are likely to have a significantly longer CICU stay. Our study has tried to fill the lacunae with regard to AKI in adults undergoing surgery for CHD. However, there is a need for more studies with larger cohorts involving more complex surgeries to truly estimate the incidence and potential risk factors for AKI in this group of patients.